Vulnerability in gnutls (CVE-2026-42009)
Summary
Vulnerability in gnutls (CVE-2026-42009). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-42009 has been found in gnutls.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "gnutls CVE-2026-42009" on the vendor's site.
CVE-2026-42009 (gnutls) — CWE-475 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-475) exists in gnutls.
Check the vendor advisory for the affected versions of gnutls.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'gnutls' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'gnutls' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
gnutlsを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Alpine Linux ALPINE-CVE-2026-42009 gnutls Fixed in: 3.8.13-r0
- BellSoft Alpaquita BELL-CVE-2026-42009 gnutls Fixed in: 3.8.13-r0
- Debian DEBIAN-CVE-2026-42009 gnutls28 Fixed in: 3.7.1-5+deb11u10
- Ubuntu UBUNTU-CVE-2026-42009 gnutls28 Fixed in: 3.4.10-4ubuntu1.9+esm3
References
- advisory access.redhat.com
- advisory bugzilla.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- web nvd.nist.gov
- web github.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web secalert@redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web security.access.redhat.com
- web access.redhat.com
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- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com